ORIGINAL ARTICLE Influence of process parameters on kerf geometry and surface roughness in Nd:YAG laser cutting of Al 6061T6 alloy sheet C. Leone 1,2 & S. Genna 2 & A. Caggiano 3,4 & V. Tagliaferri 2,5 & R. Molitierno 6 Received: 11 December 2015 /Accepted: 22 March 2016 # Springer-Verlag London 2016 Abstract In the present study, fine laser cutting of aluminium alloy 6061-T6 sheets, characterised by light reflection and heat conductivity, by means of a 150-W multimode lamp pumped Nd:YAG laser is investigated through an experimen- tal testing campaign. Design of experiments (DoE) and anal- ysis of variance (ANOVA) are adopted to study the influence of the process parameters on the kerf geometry and surface roughness. The results show that the laser allows cutting 1- mm-thick AA6061-T6 sheets with a cutting speed up to 700 mm/min, obtaining narrow kerfs (smaller than 200 μm), a fine taper angle (lower than 4°), a low dross height (about 40 μm) and a roughness average, Ra, around 4 μm. Keywords Pulsed laser . Aluminium alloy 6061 . Kerf geometry . Roughness . ANOVA . Design of experiments 1 Introduction Aluminium alloys are widely used in several advanced manufacturing industries due to their unique performance re- lated to light weight, high strength and stiffness to weight ratio, high corrosion resistance and high thermal and electrical conductivity, non-toxicity and ease of formability and machin- ability [1, 2]. Thanks to their properties, these alloys found their main applications in aerospace components, automotive and maritime applications, electrical appliances, consumer du- rable, portable tools and sport equipments [2]. Aluminium alloys can be easily cut through a number of different material removal processes, such as punching, ma- chining (profiling), abrasive water jet and electrical discharge machining. However, when small and complex 2D geometries with high productivity are required, the most common, flexi- ble and fast process for cutting is represented by laser beam cutting (LBC) [3, 4]. Compared to traditional technologies, laser machining offers several benefits such as the absence of mechanical contact and tool wear, no need for complex fixtures and the possibility to create complex shapes and ac- curate geometries with narrow kerfs on almost all categories of materials including metals, non-metals, ceramics and com- posites [5–13]. Laser cutting processes are based on a thermal interaction: when the beam radiates the material, part of the laser radiation is absorbed causing melting, vaporization or chemical state change of the material which can be easily removed by a pressurized assistant gas jet. The material re- moval rate (MRR) and the kerf profile characteristics (geom- etry, roughness and heat-affected zone) are a function of the process parameters, such as the type of adopted source (in- cluding the wavelength and the beam quality), the average power, the cutting speed, the focus position and the beam spot dimension, the type of assistant gas and its pressure. Moreover, in case of pulsed laser sources, the MRR and kerf * C. Leone claleone@unina.it 1 Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Ce), Italy 2 CIRTIBS Research Centre, University of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy 3 Department of Chemical, Materials and Industrial Production Engineering, University of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy 4 Fraunhofer Joint Laboratory of Excellence on Advanced Production Technology, P.le Tecchio 80, 80125 Naples, Italy 5 Department of Enterprise Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy 6 MBDA Italia Spa, Via Calosi 1, 80070 Bacoli (NA), Italy Int J Adv Manuf Technol DOI 10.1007/s00170-016-8667-4